Device for forming ribbons of resin-impregnated strands of filaments



1970 c. RAGETTLI 3,551,255

DEVICE FOR FORMING RIBBONS OF RESIN-IMPREGNATED STRANDS 0F FILAMENTS Filed March 24, 1967 4 Sheets-Sheet 1 lwveu'roa CH nus-mu RAGETTLI 6 -16%, MW, Vd -bm Dec. 29, 1970 c. RAGETTLI 3,551,255

DEVICE FOR FORMING RIBBONS OF RESIN-IMPREGNATED STRANDS OF FILAMENTS Filed March 24, 1967 4 Sheets-Sheet 2 INvEN'roR Cumsnm Emu-m 51 1/ 3 0%, ATTY5.

Dec. 29, 1970 c. RAGETTLI 3,551,255

DEVICE FOR FORMING RIBBONS 0F RESIN-IMPREGNATED STRANDS 0F FILAMENTS Filed March 24, 1967 4 Sheets-Sheet 5 luvem-on Cumsmm RAG E'T'I'Ll A'r'rvs.

United States Patent 3,551,255 DEVICE FOR FORMING RIBBONS OF RESIN- IMPREGNATED STRANDS OF FILAMENTS Christian Ragettli, Zurich, Switzerland, assignor to Metal Containers Limited, London, England, a company of the United Kingdom Filed Mar. 24, 1967, Ser. No. 625,702 Claims priority, application Great Britain, Mar. 24, 1966, 12,997/ 66 Int. Cl. B32b 35/00 US. Cl. 156-434 Claims ABSTRACT OF THE DISCLOSURE A device for forming ribbons of resin-impregnated strands of filaments for use in making filament wound vessels including a plate-shaped member having a series of laterally spaced grooves which converge at the exit end and a series of passages to provide synthetic resin to each groove individually.

The present invention relates to filament wound vessels and, more particularly, to a method and means for forming a ribbon composed of a plurality of synthetic resinimpregnated strands of filaments for use in forming filament wound vessels such as containers, tubes and conduits.

Because of the economy and the time involved, it is preferred to wind filament wound vessels by utilizing ribbons that are made from a plurality of strands of filaments. When using such ribbons, it is desirable to insure that the strands comprising the ribbon are substantially coplanar so as to minimize any problems which might develop when multiple layers of strands are to be used in forming the filament wound vessel.

Another requisite is that the ribbons should be compact in character. The compactness, will, of course, vary depending upon the end use to which the vessel is to be put; but it is generally necessary to provide ribbons which do not have any substantial voids or interstices between individual strands.

In forming the ribbons care must be taken to make sure that there is no localization of resin which would hamper the compactness of the ribbon. On the other hand, the method and means of impregnating the ribbons should be carried on in such a manner that each strand is uniformly coated.

An object of the present invention is to provide a method and means for bringing together individual strands of filaments to form ribbons for use in filament winding while controlling the amount of synthetic resin that is applied to the strands.

Another object of this invention is to provide a method and means for forming ribbons of the above-described type characterized by their compactness and substantially coplanar nature.

A still further object is to provide the method and means for forming ribbons of the above-described type wherein the supply of synthetic resin to the individual strands is controlled so that there are no localized excesses on the strands comprising the ribbon. A related object is to provide a method and means for assuring that a necessary amount of synthetic resin is supplied to each individual strand so that the ribbons formed have substantially no voids or interstices.

Other objects and advantages of the invention will become apparent as the following description proceeds, taken in conjunction with the accompanying drawings in which:

FIG. 1a is a plan view of the entry end of a device for forming compact ribbons of synthetic resin-impregnated strands of filaments in accordance with this invention;

3,551,255 Patented Dec. 29, 1970 FIG. 1b is a plan view of the central portion of the device illustrated in FIG. 1a;

FIG. 1c is a plan view of the exit end of the device illustrated in FIG. In;

FIG. 2 is a cross-sectional view taken along the line 2-2 of FIG. 1a illustrating a part of the means for supplying synthetic resin to the strands;

FIG. 3 is a cross-sectional view taken along the line 33 of FIG. 1b showing the inlet part of the means of supplying synthetic resin to the strands;

FIG. 4 is a cross-sectional view taken along line 44 of FIG. 1c illustrating the area in the exit end of the device shown in FIG. 1a and adjacent the inlet for the synthetic resin;

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 1a showing the width of a groove in the entry end of the device illustrated in FIG. 1a;

FIG. 6 is a cross-sectional view taken along the line 66 of FIG. lb illustrating the decreased width of a groove in the central portion of the device illustrated in FIG. 1; and

FIG. 7 is a cross-sectional view taken along the line 77 of FIG. 10 showing the further decreased width of a groove in the exit end of the device illustrated in FIG. 1.

While the invention is susceptible of various modifications and alternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. It should be understood however that it is not intended to limit the invention to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as expressed in the appended claims.

Turning to the drawings, FIGS. 1a through 10 illustrate an exemplary device for forming ribbons from strands of filaments according to this invention. In accordance with one feature of the method of forming a compact ribbon a plurality of strands are first formed into substantially a coplanar relationship with the individual strands being spaced a lateral distance from each other. A plurality of strands are forwarded to the device of this invention in a coplanar relationship and spaced a lateral distance from each other. Such strands are then passed through the device of this invention so that the coplanar and lateral distance relationships are initially maintained.

Thus, the portion of the device of this invention illustrated in FIG. 1a includes a plate-shaped member 10 having a series of laterally spaced grooves 12 extending from the entry and, indicated at 14, through the exit end shown in FIG. 1c. The exemplary device illustrated is adapted to accommodate 20 strands; however only four grooves have been illustrated. The remaining grooves are represented only by their chain dotted center lines.

The strands, forwarded by means not shown, enter the plate-shaped member 10 at the entry end indicated at 14 and are maintained both in a coplanar relationship and a lateral distance from each other by moving each of the strands into a particular groove.

In accordance with another aspect of the method of this invention the lateral distance between the strands is continuously decreased while the strands are moved through a finite longitudinal distance until adjacent strands are substantially contiguous to each other. Thus, as is shown in FIGS. 1b and 1c the laterally spaced grooves 12 converge towards each other; and, at the exit end, indicated at 16, the adjacent strands are substantially contiguous with respect to each other.

In accordance with another feature of the method of this invention there is applied to the strands a controlled amount of a synthetic resin to individually impregnate each strand. While the strands are preferably composed of glass fibers and the synthetic resin is an epoxy resin,

these aspects are not critical features of the invention and any suitable materials that have been used for filament winding are suitable.

The synthetic resin is applied to each of the strands individually after the strands have begun to move through the finite longitudinal distance previously described. In the illustrated embodiment synthetic resin is introduced through an inlet opening 18 as shown in FIGS. 1b and 3 which is adapted to be connected to a source of synthetic resin (not shown). The inlet opening 18 can be formed in a socket which also can constitute the means for mounting the device of this invention on the winding machine to be used in the formation of filament wound vessels.

The means for supplying synthetic resins to the grooves 12 further includes a central transporting canal 20 connected to the inlet opening 18 and extending towards the entry end of the device of this invention.

Adjacent the entry end of the device of this invention the central resin transporting canal 20 has a pair of lateral passages 22 which branch outwardly from the canal and pass under the grooves 12 of the device.

The resin feed passages 24 extend from the lateral passages 22 and each open into one of the grooves 12. The central transporting canal 20 can be threaded as indicated at 26 so that a plug for closing the end can be introduced. Adequate control of the amount of resin supplied to each of the strands, and thus the ribbon itself, can easily be effected by merely controlling the amount of resin fed to the inlet opening.

In accordance with still another aspect of this invention the synthetic resin applied to the strands is maintained in contact with the individual strand while the strands are moving through the finite longitudinal distance that has been hereinbefore described. The sythetic resin that has been introduced through the feed passages 24 is maintained in contact by the physical presence of the grooves 12 as the strands move through the device of this invention. This allows the impregnation of the individual strands to be carried out with uniform application and no localization of resin.

In a preferred embodiment of this invention, the amount of resin that is maintained in contact with the individual strand while the strands are moving through the finite longitudinal distance is decreased in a step-wise fashion. As illustrated in FIGS. 14 through 10 and through 7, the width of each of the grooves 12 decreases from the entry end to the exit end while the depth of the grooves remains substantially uniform. The decrease in width of the grooves is accomplished in a step-Wise form so that the shoulders immediately surrounding the beginning of the decreased width can serve to hold back large drops of synthetic resin and act as a scraping device to prevent an excess of resin from penetrating to the narrow exit end of the grooves 12 to prevent clogging the exit end. Thus, the width of the grooves 12 is successively decreased from the entry end to the exit end as indicated at 28 and 30.

While only two step-Wise reductions in width of the grooves have been shown, it should be understood that the number may be varied as desired. Moreover, the rate at which adjacent strands converge (and the finite longitudinal distance through which the strands move) can be modified as desired. The convergence should, however, be gradual enough so that the ribbon which is formed is compact and there is no necessity for imposing external means at the exit end to maintain adjacent strands in a contiguous relationship, The finite longitudinal distance 4 should also be long enough to allow the synthetic resin to uniformly coat the individual strands. If desired, braking means such as pins to slow the speed of the strands can be provided adjacent the exit end of the device.

It can thus be seen that the present invention has provided a method and means for forming ribbons composed of a plurality of strands of filaments which meet all of the requirements for use in forming a filament wound vessel. The ribbons formed are compact in nature, have substantially no void area or interstices and are coplanar. The impregnation of the strands with synthetic resin is accomplished individually and in such a manner that individual strands .do not receive any excesses yet the strands are uniformly impregnated.

I claim as my invention:

1. A device for forming a compact ribbon of strands of filaments impregnated with synthetic resin which comprises first means to maintain a plurality of strands in a substantially coplanar relationship and spaced a lateral distance from each other, second means connected to said first means to cause the lateral distance between the strands to gradually decrease while moving the strands through a finite longitudinal distance until adjacent strands are substantially contiguous to each other and third means to apply synthetic resin to impregnate each strand individually after the strand has began moving through the finite longitudinal distance, said second means being capable of maintaining the applied synthetic resin in contact with the individual strand while the strands are being moved through the finite longitudinal distance.

2. A device for forming a compact ribbon of strands of filaments impregnated with a synthetic resin which comprises a plate-shaped member, said plate-shaped member having a series of grooves extending the longitudinal dimension of said plate-shaped member and which are located a lateral distance from each other at the entry end and are converged at the exit end of said plate-shaped member and means for supplying synthetic resin to said grooves adjacent the entry end.

3. The device of claim 2 wherein the width of each of said grooves decreases from said entry end to said exit end while the depth of said grooves remains substantially uniform.

4. The device of claim 3 wherein the width of each of said grooves is decreased in a step-wise fashion.

5. The device of claim 2 wherein said means for supplying synthetic resin to said grooves includes an inlet opening adapted to be connected to a source of the synthetic resin, 2. central resin transporting canal connected to said inlet opening, lateral passages branching from said central resin transporting canal and resin feed passages extending from said lateral passages and each opening into one of the grooves adjacent the entry end of the plateshaped member.

References Cited UNITED STATES PATENTS 2,751,320 6/1956 Jacobs et al 156-441X 2,865,799 12/1958 Gonsett 156*434 3,208,896 9/1965 Lang et al 156441 3,215,577 11/1965 Sinnott 156-441X 3,335,046 8/1967 Current et a1. 15644l BENJAMIN R. PADGETI', Primary Examiner U.S. Cl. X.R. 

